Hermit crabs are born in the ocean. A female tosses her eggs into the sea, with the strongest surviving to evolve into hermit crabs. It’s possible to breed hermit crabs in captivity, albeit rare.
You’ll need to home a responsive female in a separate breeding tank, replicate the ocean experience with a saltwater pool in this tank, and add a sexually active male. It may take a choice of partners before a female agrees to breed.
Don’t adopt hermit crabs will the sole intention of breeding, as this will usually end in disappointment. You’ve been very fortunate if you convince two hermit crabs to breed.
Do Hermit Crabs Breed?
Hermit crabs don’t reproduce asexually, so a male and a female are required to mate. If the mating is successful, the female lays eggs in the sea.
Once these eggs are ready to hatch, the female tosses them into the ocean. Marine Ecology Progress Series explains that some hermit crabs climb trees to do this safely. From this point, the baby hermit crabs are on their own.
Can you see the problem with breeding hermit crabs in captivity? No ocean means nowhere for the female to release her eggs. You can potentially trick females into leaving eggs in a pool of saltwater in an enclosure, but this can be tricky.
Hermit Crab Breeding Process Explained
The breeding behavior of hermit crabs can vary, depending on the species. In most cases, it’ll follow the same parameters:
- Females release a pheromone that announces she’s ready to breed.
- Males detect this pheromone and approach.
- The male hermit crabs fight over who will breed with the female.
- One of the males wins out, and the female decides if she is still interested.
- If the female wishes it to be so, the hermit crabs mate.
Hermit crab mating can resemble fighting to the untrained eye; it looks like the male is attempting to drag the female out of her shell. In reality, hermit crabs mate within their shells to stay safe. Males have a large penis that ensures females can be inseminated without leaving the shell.
During mating, the male deposits spermatozoa into the gonopores of the female. These are two tiny holes above the third set of legs. If fertilized, the female carries eggs within her abdomen for around a month. Once released, the hermit crab life cycle commences.
Hermit Crab Life Cycle
Once eggs are cast into the sea, thousands of tiny larvae, known as zoeae, emerge from these eggs. These zoeae float in the sea. Many eat each other, while others become snacks for marine wildlife.
If the zoeae survive for around 60 days, they make their way to land, which commences the next stage of the life cycle. At this point, zoeae evolve into megalopae. A megalopa is roughly the size of a fingernail and resembles a spider or tiny lobster.
The megalopa life stage lasts around 30 days. After this, the megalopa burrows under the sand of a beach. During this period, it molts and evolves. When the megalopa surfaces, it’s a junior hermit crab, so it’ll seek a shell and begin its new life.
What is the Ideal Hermit Crab Breeding Age?
Hermit crabs don’t experience menopause, so they can breed at any age. Most hermit crabs are driven to reproduce while young, though.
Life is dangerous for hermit crabs because they’re at the bottom of the food chain. Hermit crabs can live for decades, but few are so lucky. This encourages hermit crabs to breed to keep their species alive.
Size is also a concern. The larger a hermit crab grows, the harder it becomes to find an appropriately-sized shell. Females, in particular, are wary of this because they need to find a large enough shell to accommodate an egg sac, but not so big that it impedes mobility.
How Often Do Hermit Crabs Breed?
Female hermit crabs will breed multiple times in their first year of life.
Pregnancy freezes molting and growth cycles. The more hermit crabs reproduce, the longer they’ll fit into small shells, which are easier to find.
Male hermit crabs, meanwhile, will breed as often as permitted. Hermit crabs are sociable and live in large groups of up to 100, so males rarely lack mating opportunities.
Hermit crabs don’t take active roles in raising their young but welcome more arrivals to a colony. For hermit crabs, there’s safety in numbers. Ergo, the more hermit crabs breed, the more friends will be available to offer protection.
Shells are in short supply, especially as hermit crabs prefer to occupy vessels that once held another hermit crab. When a hermit crab dies, another crab claims its vacant shell.
This means they need a constant availability of shells. The more hermit crabs live in the area, the likelier it is to find a new shell. Current Biology describes this phenomenon as “social dependence.”
Do Hermit Crabs Breed in Captivity?
Mating in captivity is possible, but it requires a great deal of patience and good fortune. However, mating remains rare among captive hermit crabs.
This is primarily due to unfamiliarity with the environment. As discussed, female hermit crabs rely on ocean water, so you’ll need to trick a female into thinking she’s in the wild to inspire breeding.
Even then, it takes certain circumstances because females are fussy about choosing a mate. Also, males must be completely relaxed and devoid of stress and anxiety.
If these criteria are met, you may yet successfully breed two captive hermit crabs.
How Do You Breed Hermit Crabs in Captivity?
If you adopt hermit crabs to breed them, disappointment is likely, but this does mean you can keep hermit crabs of the opposite sex together in a shared aquarium. You don’t need to sex hermit crabs.
The circumstances must be just so if you attempt to breed captive hermit crabs. To be successful, the natural habitat must be replicated.
Remember, the female hermit crab will seek out saltwater for birth.
Here’s a step-by-step process of breeding captive hermit crabs:
Create A Breeding Tank
The first thing to do is set up a special breeding tank. Don’t attempt to breed hermit crabs in their standard enclosure because you’ll need a specialist environment for this practice.
Pick up a 10-gallon aquarium to use as your breeding tank, and set this up as you would a standard habitat. Keep it away and from direct sunlight or any draughts.
Include the following in the habitat:
- A sturdy lid that can’t be easily lifted or put a weight on the top.
- A humidity of 80% (use a hygrometer).
- A temperature of around 80 degrees Fahrenheit.
- A minimum of six inches of substrate (sand or soil, ideally the former).
- Drinking water
- Climbing apparatus
- Hiding places
- Other toys for recreation
If there’s to be any chance of the hermit crabs mating, they must be completely content.
Replicate Ocean Conditions
If the female hermit crab is to be tempted to breed, you’ll need to recreate an oceanic environment, which involves bringing the sensation of the sea to the breeding tank.
In addition to drinking water, you’ll need to create a mini ocean where the female will deposit her eggs when the time comes. Until then, it’ll be used as a saltwater bath for the tank’s occupants.
Find a vessel that’s large enough to act as a pool. If you successfully breed hermit crabs, thousands of eggs will be laid, which means there must be plenty of additional space.
Use filtered or bottled water in this pool, heated to 72 and 80 degrees Fahrenheit. Never use tap water because this is toxic to hermit crabs; the chlorine will kill hermit crabs.
You need to add marine salt, not table salt, because table salt contains iodine, which is dangerous to hermit crabs. You can get marine salt from an exotic pet store.
Once ready, apply this pool to the aquarium. Ensure that it’s easy for hermit crabs to get in and out by providing a ramp, vines, or netting because these will provide the hermit crabs with something to grip as they enter and exit the water.
Change the water regularly, always ensuring it’s salted before returning to the tank. The presence of saline water will go some way to convincing a female hermit crab to breed.
Choose Your Timing
You’ll improve your chances of successful breeding if you time your attempt appropriately. Wild hermit crabs don’t have a breeding season. In captivity, it is believed that hermit crabs prefer to breed between February and August, but June and July are the likeliest.
If your female has recently completed a molt at the height of summer, so much the better. Females are most receptive to breeding at this point in their life cycle. You can’t control when hermit crabs molt.
If you notice pre-molting signs in spring, start preparing a mating tank. Be prepared to move your female as soon as she’s active again after concluding a molt. Don’t attempt to breed her until she has destressed and rejoined her tankmates.
You may find males congregating around a female in a shared tank, which suggests she’s ready for mating. According to Ecological Research, males are more interested in females ready to breed.
Identify a Female Hermit Crab
A young female (ideally 1 year or younger) that has just molted is optimal. Older females, or those yet to molt, are less likely to respond well to advances from males.
To check if a hermit crab is female and sexually mature, wait for her to emerge from her shell. Handle her several times until she’s comfortable with this activity. Once you’ve gained trust, verify her sex.
Once you know what you’re looking for, it’s simple to sex hermit crabs. Females will have the following physical characteristics:
- Smooth, hairless legs (males have hairier legs).
- Three feathery appendages on the left of the legs protect and carry eggs once inseminated.
- Gonopores above the third set of legs.
Female hermit crabs are particular about choosing partners, so you’ll need patience. As discussed in the Journal of Crustacean Biology, mating depends on if the female is receptive.
Don’t switch the female until all options of male partners have been exhausted because hermit crabs remember their tankmates. A female may be open to mating but is awaiting her preferred companion.
How Do Hermit Crabs Choose a Mate?
Hermit crabs will usually choose a mate based on size.
As explained by Behavioral Ecology, males prefer females of comparable size, while females often gravitate toward a larger male.
Males that detect sexual reciprocity from a female guard her jealously, leading to males attacking each other. According to the Journal of Zoology, the female may lose interest in mating due to the delay.
All the same, the Journal of Ethology claims that some female hermit crabs enjoy inspiring such competition. This helps determine the dominant male in a colony.
Introduce a Male Hermit Crab
You’re looking for a sexually mature male, which means hairy legs and no gonophores.
If a male is keen to mate, it’ll gently rock the female’s shell. What happens next depends on whether the female is interested. She’ll either respond by emerging and mating will begin, or she’ll ignore the advances and remain in her shell.
If no mating occurs within 24 hours, remove the male and replace it with another. Female hermit crabs don’t release pheromones for more than a few days at a time.
Keep trying with different males; there’s no guarantee of success, but it improves the odds.
Checking for Pregnancy
A female hermit crab that has been successfully inseminated will head to a saltwater pool, which is where she’ll lay her eggs. If you spot your female bathing after mating, step one is complete. Leave the male in the tank for company during the pregnancy.
Female hermit crabs gestate for around 30 days, so you’ll spot a clutch of eggs on the left of the female’s body during this time. Female hermit crabs can produce between 800 and 50,000 eggs, depending on their size—the bigger the hermit crab, the more eggs.
Nowhere near this many eggs will become hermit crabs, which is why females create so many eggs. This number of eggs assists with the propagation of the species.
These eggs will be the color of red bricks while they grow. As the 30-day gestation cycle ends, they’ll start to fade to a dull gray, which means the eggs are ready to hatch.
This is when a female would toss her eggs into the sea, which isn’t an option in captivity.
This is why it’s so critical that your female believes her saltwater pool is an ocean. If this is the case, she’ll drop her eggs in this body of water.
From here, the eggs will hatch, and you’ll have baby hermit crabs. The female won’t play any further role in raising her offspring, so you can return her and her mate to the shared tank.
How To Raise Baby Hermit Crabs
Pat yourself on the back if your female hermit crab lays eggs in her saltwater pool because you’ve already achieved more than many experts. Unfortunately, the job is only half complete.
The zoeae of hermit crabs are so small that you may mistake them for bubbles in the saltwater. These zoeae must remain in saltwater for the first 60 days of their life.
Throughout this period, Darwinism will come to the fore. Your hermit crabs may have produced thousands of eggs, but many of the larvae will consume each other, and many more will die through lack of strength or unsuitable conditions.
The saltwater that houses the zoeae must be changed regularly. The larvae can’t survive out of the water, so you’ll need to ensure that you have a regular source of water vessels to alternate.
Use a pipette or syringe to drip-feed these zoeae. Live plankton is an ideal food source, but powdered spirulina, marine infusoria, or marine copepods are suitable alternatives.
Evolution into Hermit Crabs
The zoeae that survive will crawl into the substrate. At this point, they’ll become land dwellers. Consider removing the saltwater pool and replacing it with a smaller, safer water vessel for bathing.
Hermit crabs can eat frozen krill, crayfish, or shrimp granules during the megalopa stage. Many will struggle to survive in captive conditions of heat and humidity, and some will also cannibalize others.
Offer plenty of small shells because the more protection a megalopa has, the better its odds of survival. As mentioned, after 30 days, surviving megalopae will burrow, molt, and grow.
They can live together if your aquarium is large enough and you trust the incumbent hermit crabs. Alternatively, keep them in the mating tank until you deem them large enough to mix safely.